VICTOR BLACKWELL, CNN ANCHOR: I'm Victor Blackwell. Always good to be with you. Six o'clock here on the East Coast. This is NEW DAY SATURDAY.

We've got a lot going on this morning. You know, this is being called, one story we're following, the worst security hole the Internet has ever seen. And now your most vulnerable information may be at risk. We'll talk about that.

PAUL: And, hey, have you heard about the president's tax returns? Well, they're in. He took a hit in income last year. We're going to talk about that, too.

BLACKWELL: Yes, making less money.

But we're going to start with the search for Malaysia Airlines Flight 370. It has now been 36 days since that flight vanished. Investigators -- good news here -- may be closer than ever to locating that missing jetliner.

PAUL: Yes, we know right now at least 10 planes and 14 ships are scouring the smallest search zone to date. That's the good news. Crews are focused on an area in the Indian Ocean now that's about the size of Massachusetts and Connecticut combined, just to give you some perspective there. Now you may recall at one point the search zone was about the size of the continental U.S., so definitely making some progress.

BLACKWELL: Yes, progress there and a boost of confidence overnight from Australian Prime Minister Tony Abbott. He says officials believe four pings detected by a high-tech U.S. pinger locator this week are coming from one of the plane's black boxes.

(BEGIN VIDEO CLIP)

TONY ABBOTT, AUSTRALIAN PRIME MINISTER: There have been numerous, numerous transmissions recorded, which gives us the high degree of confidence that this is the black box from the missing flight. What we're now doing, given that the signal from the black box is rapidly fading, what we are now doing is trying to get as many detections as we can so that we can locate -- so that we can narrow the search area down to as small an area as possible.

(END VIDEO CLIP)

PAUL: This comes at a critical time in the search. The batteries on the plane's black boxes are quickly fading, if they're not dead already, in fact.

BLACKWELL: But officials warn recovering these black boxes, this is a massive task, because those signals are coming from about three miles beneath the surface.

PAUL: So let's put this in perspective. Flight 370 is about 200 feet wide, 242 feet long, which means from where those signals are coming from, you'd pass the Statue of Liberty, the Eiffel Tower, and the tallest building in the world on the way down to it.

BLACKWELL: Wow. Let's bring in CNN's Will Ripley. He's in Perth, Australia. Will, we can see that the sun is setting there, and soon the search planes should be coming in. What's the latest there?

WILL RIPLEY, CNN CORRESPONDENT: Yes, you know, the visual search is wrapping up for the day. And you know, you talked about how far we've come, mentioning the size of the search area. At its biggest point, more than 3 million square miles.

Now we're down to roughly 16,000 square miles. Still a large area, but certainly a lot of progress has been made. But we're missing one key piece here. Still, 36 days in, we do not have one single piece of physical debris from Flight 370.

There's also the underwater search, which continues to happen around the clock. That's the listening devices. Both the U.S. Navy's towed pinger locator, and then there's a British ship listening. The Australian air force has been dropping those sonobuoys with listening devices, as well.

But it's been now more than three days since we've last detected a ping that is suspected to be from an airplane black box. So the question now is going to be when does the search transition from listening to actually physically searching, using the underwater submersible? That's a question that we could get answered this week. But they want to keep listening as long as possible to make absolutely sure that they're -- that these devices are not emitting anymore pings.

PAUL: Is this the only place they're searching at this point, Will? I mean, there were so many different search areas. Three even just as of last weekend. Have they ruled out those areas completely at this point?

RIPLEY: Well, we know that the visual search area and then the underwater search area are separated by several hundred miles. And really, the underwater search area is where they're focusing as far as the location, the potential location of these -- these black boxes. They feel that, even though we don't have any physical evidence, that these pings that they've detected are solid enough that it's worth devoting a considerable amount of time and energy to that particular area.

As far as the visual search area, you know, they've been trying to calculate the currents to track, you know, if the plane went down in a certain spot, where in these 36 days would the debris have floated to? And so that's what's happening. They feel like they're onto something but still a lot of work ahead, guys.

PAUL: All right. Will Ripley, thanks so much for the update. We appreciate it.

And let's discuss the latest on the investigation, too, with CNN aviation analyst and former inspector general with the U.S. Transportation Department Mary Schiavo.

BLACKWELL: We've got Simon Boxwell also with us. He's an oceanographer with the National Oceanography Center, joining us live now from London.

Mary, I want to start with you. There is this level of optimism now because of the comments from Prime Minister of Australia Tony Abbott, saying that there's a high degree of confidence, kind of doubling down on these signals.

But I want to walk with you, and you've been here in that chair. I've been here as we've heard these optimistic statements from Abbott in the past. He said that there's new and credible information that's come to light. That was March 19. Turned out to be nothing. March 22, "We now have a number of very credible leads." Turned out to be a dead jellyfish. Are we investing too much in the optimism of the prime minister?

MARY SCHIAVO, CNN AVIATION ANALYST: Well, in the optimism of the prime minister, yes. But in the reports of Angus Houston and the fact that they actually have pings, some of them as long as two hours plus, that's pretty good. I mean, there have been other accidents. And based on other accidents in the past, sometimes they don't even have that much to go on, and they're still able to get those black boxes.

So I do think there's cause for optimism, but no matter how many pings you get, you still have to have a long -- it's long, hard work to get those submersibles down there and actually find the black boxes and then figure out where they are and how to get them up. So there's lots to go yet. But the pings are good.

PAUL: OK, so Simon, let me ask you, because I think a lot of people are watching this and they're saying, if you've got this narrowed down to, you know, a 15,000-, 16,000-square-mile radius now, which is where we're sitting, why do you not send at this point that Bluefin drone in the water to see what it can do?

SIMON BOXWELL, NATIONAL OCEANOGRAPHY CENTER: They need down a lot more than 15, 16,000 square miles. And in fact, if they can identify these pings and confirm these pings are real, they're going to keep looking until they're confident that things are stop being sent. We're well past the 30-day design limit of the pingers.

So you know, we might expect to see an extra five, six days, from the sensors (ph) effectively, but they are pretty much dead now. So it doesn't mean that, if they rely on the ping data, we're not looking at 15,000 miles. We're probably looking at an area about the size of the city of Washington. So it's come down a lot more. That becomes feasible.

You know, if you're sending one of these ROVs or the AUVs down, they're moving very slowly, about 4 miles an hour. They're surveying a very small area. They'll sort of be looking beside. These only may be 50 meters, 100 meters. That will take a long time, unless they can get it down.

So this is why they put so much effort on the pinger first. Otherwise, it's just a random deployment of the AUV.

BLACKWELL: So Mary, the follow-up to that statement I'm going to bring to you. If over the next 24 hours, 48 hours there is no new ping, and let's say, you know, 36 days, the batteries on the pingers have expired. How long do you expect the wait before they will send down the Bluefin with whatever area or whatever information they have, because they don't expect the batteries to send out another signal?

SCHIAVO: Oh, I think they're already getting ready to do that. The United States sent a supply ship in, the Cesar Chavez, a logistics ship. They're getting the stuff on site and ready to go.

But remember, it takes a long time just to deploy them and get them down. They have to release them and get them all set to go. According to the Bluefin specs, it can cover up to 40 square miles a day on mapping, but they might have it go slower than that to get really a clear picture.

So I think they're prepared to get started doing that, just based on sort of the logistics ship that has been sent in and what they're ready to do. But again, I caution, there was -- there was a crash in the Java Sea a number of years ago. And it crashed in January, and they got the black boxes in August.

The world record depth crash was in the Indian Ocean, 16,000 feet. And they got those in two days. So you never know what -- how long the next step is going to take.

PAUL: Simon, does it bother you that they haven't seen one piece of debris up to this point?

BOXWELL: No, not particularly. I mean, they're looking for surface debris. And let's face it, over the past month, they've been chasing rainbows. They've been looking at the wrong place. It's only in the last week that the search area is focused on this far north site. Far further north than anything before.

And if we look at the currents in this area, the western Australian current takes material further north. And so they've been looking in the wrong place. The satellite data so far has proven to be a red herring. They really do need sightings from ships and from aircraft.

But this far in, because we're so far past the crash date, to be honest with you, finding the wreckage would confirm that it's down there somewhere. Although beyond reasonable doubt, which it is, backtracking from wreckage six weeks on isn't going to give us much information.

So the real hope lies in these ping data and getting an AUV down. As Mary said, the AUV can cover 40 square miles in a day. But that's working shallow. And we're right on the limit of the depth. She's rated to 4,500 meters, 4,500 meters. We're working at 4.5 kilometers, about 15,000 feet.

So everything is right on the limit. It takes time to get the system down there, two or three hours just to get it down to the right depth. And then it only gives them about two or three hours on survey before it comes back up. Now bear in mind, the AUV they're using doesn't have an umbilical to the surface. They don't see the data until it comes back to the surface, and they can download it.

BLACKWELL: A lot of progress has been made. But still a lot of work to do. Mary Schiavo, Simon Boxwell, thank you both.

PAUL: Now, at this point in the search of this plane, the tech team on board the Ocean Shield has one of the most crucial jobs: detecting the sounds that are meant to lead investigators to the flight's black boxes. We're going to show what it takes to pick up a ping.

BLACKWELL: Also, another tragic story we're following. Several teenagers killed in this fiery bus crash in California. We'll take a closer look at just what went wrong here.

(COMMERCIAL BREAK)

(BEGIN VIDEO CLIP)

ABBOTT: What we're now doing, given that the signal from the black box is rapidly fading, what we are now doing is trying to get as many detections as we can so that we can locate -- so that we can narrow the search area down to as small an area as possible. Once that's been done, and I don't want to speculate on when that might be, once that's been done, it's our intention to then deploy the submersible, which will conduct a sonar search of the seabed. And based on the sonar search, attempt to get a visual on wreckage.

(END VIDEO CLIP)

BLACKWELL: That's Australian Prime Minister Tony Abbott. And when he says "we," that group includes Americans, hard-working people who are technically listening for the pings that everyone hopes will continue.

PAUL: This is such a monotonous task. It sounds basic and really rudimentary when you think about it. But as CNN's Brian Todd explains, so much can get in the way of just picking up a ping -- Brian.

BRIAN TODD, CNN CORRESPONDENT: Christi and Victor, no one knows their names. They spend hours and days in an isolated, confined space in the middle of the Indian Ocean, often staring at nothing, listening to silence. But right now, the sonar technicians aboard the Ocean Shield may have the most important jobs in this entire search effort.

(BEGIN VIDEOTAPE)

TODD (voice-over): We're hanging on what they're hearing. The hopes of finding the black boxes from Malaysia Airlines Flight 370 rest on a few anonymous technicians, hunkered down inside a control bunker on the Ocean Shield.

MIKE DEAN, DEF. DIRECTOR FOR SALVAGE & DIVING, U.S. NAVY: Day and night, you know, there is no break. They're pretty much on all the time. And what they do is so important to us.

TODD: We went behind the scenes at Phoenix International, the company that made the towed pinger locator that's scouring the search area for black box pings. Phoenix has nine people on the Ocean Shield. Among them, sonar techs tasked with looking at monitors, listening, and listening some more.

PAUL NELSON, PROJECT MANAGER, PHOENIX INTERNATIONAL: You'll sit for days at a time, listening to nothing. And then you might hear a chirp, but you don't hear another one. So until you can duplicate it and run it back at different angles, only until then are you positive you have it.

TODD: And even then, experts say, sound in the ocean can play so many tricks on your ears.

DEAN: Several people can look at a signal and see different things. Because all they're really recording is sound energy.

TODD: False positives from fishing and research equipment left in the area; from debris and thermal conditions; from the vessel itself can also play tricks on the techs.

(on camera): Phoenix's operators on board the Ocean Shield are good at weeding out false positives. They do it by carefully monitoring the specific frequencies and the repetition rate. And in op centers like this one on-board, they're highly trained to be disciplined and to discriminate, to block out any other potential sounds.

(voice-over): Paul Nelson, who worked the search for Air France Flight 447, describes the sonar techs' work as meticulous, tedious, time devouring.

NELSON: There's two shifts. They work 12-hour shifts. So the first crew will work from midnight to noon. And the next team will work noon to midnight. You're monitoring the weather. You're watching what's coming as far as weather. You're monitoring the seas. And you're sitting in front of the screen, hoping and praying that you're going to hear something. TODD (on camera): Does it drive them a little stir crazy?

NELSON: Everyone looks forward to the meal time. That breaks up the monotony.

TODD (voice-over): Some of these techs have been doing this for more than 30 years, decades of often thankless dedication just to find that one breakthrough pattern of blips.

NELSON: Everybody is so focused on this task at hand that, once you know you have it, it's a tremendous feeling. That's the high.

(END VIDEOTAPE)

TODD: Once signals are detected and confirmed, it's reported up the chain of command. Top officials make those announcements that we all hear. And the techs simply go back to work with us still not knowing their names -- Christi and Victor.

BLACKWELL: All right, Brian Todd reporting for us. Brian, thank you.

PAUL: And listen, we're going to talk about something else, too. Because do you realize it's been four years since the death of that trainer at SeaWorld that we all talked about so much? Well, since then the shows haven't been the same. And a new court ruling means they're going to stay that way. We'll tell you what we're talking about.

BLACKWELL: And our expert panel weighs in on the important question. When should these experts stop listening and start actually looking for the black boxes? Send down that Bluefin? When should it happen? They'll weigh in. Flight 370 missing now for 36 days.

(COMMERCIAL BREAK)

BLACKWELL: It's crunch time in the search for the wreckage of Malaysia Airlines Flight 370. We'll get to more of that in a moment.

PAUL: But first, we want to get Nick Valencia for some of the other stories that are making headlines this morning. Other news, Nick. What's going on?

NICK VALENCIA, CNN CORRESPONDENT: Good morning, guys. Good to be here with you. Good to cover other news. We'll start with big news at the White House. President Obama ready to rusher in a new head of health and human services.

In a Rose Garden ceremony on Friday, President Obama announced that Kathleen Sebelius would be stepping down as health secretary and that he would be nominating Sylvia Burwell to replace her. Sylvia's -- Sebelius's resignation marks the end of a tumultuous tenure that included overseeing the botched roll-out of Obamacare.

President Obama and first lady Michelle took a bit of a pay cut in 2013. The couple reported $481,000 in adjusted gross income on their federal tax return. That's a drop of about 21 percent from last year. Their tax bill came to a bit more than $98,000. That's an effective federal tax rate of about 20.4 percent.

Now an appeals court has ruled that SeaWorld trainers still cannot get in the water with killer whales during shows like they once did. After the death of trainer Dawn Brancheau in 2010, OSHA barred staffers from performing with orcas in water unless there were barriers between them.

The publicly-traded company has not yet decided if trainers were not allowed in the water. They've not decided if they'll appeal to the U.S. Supreme court.

Now the deadly bus crash in California. Ten people were killed and more than 30 injured after a FedEx truck slammed into a bus carrying teens. The students were on their way to Humboldt State University to visit the campus. CNN's Stephanie Elam has more.

(BEGIN VIDEOTAPE)

STEPHANIE ELAM, CNN CORRESPONDENT (voice-over): The images are horrifying. A bus full of high-school students burst into flames on the side of a California highway after a head-on collision with a FedEx truck.

LUIS LOPEZ, WITNESS: I went outside, and everything was in flames already. There was a couple of explosions after that.

ELAM: The truck slamming into the bus full of high school seniors after police say it crossed over the median and into oncoming traffic.

UNIDENTIFIED FEMALE: All of a sudden, I heard a sonic boom. When I got there, everything was engulfed. And it was still spewing up black smoke.

LOPEZ: A lot of people were screaming and begging for help. With all the flames and all the smoke, it would just cover your eyes.

ELAM: Emergency crews raced to the scene to help the injured students.

UNIDENTIFIED FEMALE: Many of them had cuts, contusions, bumps and minor burns. The ones I saw, I know that there was one person when we arrived on scene that was -- unfortunately, he was on fire.

UNIDENTIFIED MALE: They were screaming for help. As I say, (UNINTELLIGIBLE) just give me help.

ELAM: At least 34 people were rushed to local hospitals. Helicopters air-lifted survivors. Others were taken by school bus and ambulances to local care centers.

UNIDENTIFIED FEMALE: I saw one gentleman on the board, and his clothes were gone, pretty much. I couldn't tell if his injuries were significant. I just kept praying. ELAM: The high-school students were on their way to visit Humboldt State University this weekend. Just hours after tweeting a picture from inside the bus, crash survivor Jonathan Gutierrez posted this picture of the crash scene, writing, "Can't believe what just happened. I was asleep, and next thing you know I was jumping out for my life."

Stephanie Elam, CNN, California.

(END VIDEOTAPE)

VALENCIA: Just such a tragic story there out of northern California. Christi, we'll throw it back to you.

PAUL: All righty. Thank you, Nick.

BLACKWELL: Thank you, Nick.

Still to come on NEW DAY, search teams desperately looking for Flight 370. We'll talk with the manufacturer of those underwater locator pingers.

(COMMERCIAL BREAK)

PAUL: It is just about -- well, it's 29 minutes past the hour right now, just in case you have to run off somewhere, hopefully you're just getting a little R&R. I'm Christi Paul.

BLACKWELL: Just stay with us. I'm Victor Blackwell. We've got a lot more this morning on the search for Malaysia Airlines Flight 370.

PAUL: Yes. Actually, a lot of news coming from the Australian prime minister this morning, who seems to be very confident, saying that four signals detected by a U.S. pinger locator are coming, he says, are coming from one of the plane's black boxes. He's that confident.

BLACKWELL: Yeah, right now at least ten planes, 14 ships are scouring the smallest search zone to date. Crews are focused on an area in the Indian Ocean about the size of Massachusetts and Connecticut combined. And you may recall that at one point the search zone was about the size of the continental U.S.

PAUL: But time is ticking away here, obviously, for search crews. I mean the batteries on the plane's black boxes are quickly fading, if they're not dead already. And officials warn recovering the black boxes is a massive task. Even though those signals were detected within 17 miles of one another, they're coming from about three miles below the surface.

BLACKWELL: So let's talk now with someone who knows these pingers likely better than anyone else.

PAUL: Yeah, Chris Portale is the director of a Dukane, a Heico company which makes that underwater locator pinger that everybody is searching for. He also got to hear and confirm the first set of pings detected by Australian search teams. So Chris, I know earlier this week you told CNN you were extremely confident the sounds were from the flight's black box. Now search teams have reported hearing four pings. Is there any doubt in your mind that sound is coming, in fact, from Flight 370?

CHRIS PORTALE, DUKANE DIRECTOR: No, there's no doubt. The acoustic signature of the beacons and the cadence that they're coming from is definitely from one of our beacons. So we're very confident that it's from there. It's got a very specific sound. You've got a pulse and a ping once every second. And that's not readily found in nature. That's why they're designed to be unique and stand out.

BLACKWELL: So it's day 36 of this search. These batteries on the pingers are required to last 30 days. Do you think that the batteries on the pingers have maxed out now? Or could there possibly be another 24 to 48 hours of battery life left?

PORTALE: In our testing, we've been able to get anywhere from 35 to 40 days. We were told that the pingers were due to have their batteries replaced next year, which would indicate that they're five years old and nearing the end of their life. So we're confident that there may be a couple of more days left, but as the battery starts to degrade, the signal is going to get weaker, so it's going to be even more difficult to hear it until it eventually can't produce enough power to send a signal out. So there could be a few more days left.

PAUL: There's been a lot of talk, Chris, that pingers should have a longer life. How hard is it to create technology to make that happen?

PORTALE: Well, we've actually created one that has a 90-day life. Out of the Air France disaster, there was a new TSO requirement that new pingers starting next year will have to have the 90-day life. We've created that, and we have it out there. But once it becomes required, the airlines are going to have to put it on there. So there is out there a 90-day beacon.

BLACKWELL: So Chris, help us understand something. A week ago when the Chinese reported hearing a ping, they said it was at 37.5 kilohertz, which is the frequency at which the pings emit the signal. But the Australian Defense Force, the ADF, says that the pings that have been detected near the Ocean Shield were not exactly at 37.5 but within the range. Explain that discrepancy, how it can still be so certain that these are pings from black boxes, from the locator but not at 37.5.

PORTALE: Well, you've got a bunch of reasons. Mostly the pressure, the temperature, and the salinity of the ocean. The audio sounds are moved around under water and it plays some tricks on it. So, it's more important less the frequency, it's more the cadence. It's more the unique manmade sound of it. And it wouldn't be unusual to detect it at the lower frequency, which is the 33.

PAUL: Hey, Chris, let's listen to Australian Prime Minister Tony Abbott here who continues to affirm that those pings coming from the locator beacon are starting to fade.

(BEGIN VIDEO CLIP) TONY ABBOTT, AUSTRALIAN PRIME MINISTER: We're now getting to the stage where the signal from what we are very confident is the black box is starting to fade. And we are hoping to get as much information as we can before the signal finally expires.

(END VIDEO CLIP)

PAUL: So if we're at day 36, gosh, I mean, Chris, you make these things. How long do you think we have?

PORTALE: I think we've got maybe a day, possibly two more. Knowing how old the batteries were. We've seen them last up to 40 days. They're certified for 30 days. So, anything after that is, you know, is bonus time, really.

BLACKWELL: So, with full battery, the search teams ideally become within, you know, a mile or two nautical miles maybe to locate this signal. With the batteries dying, how much closer do they need to be? Does the signal get weaker or does the frequency become -- or the frequency of the signal become less frequent, I guess. How close do they need to be?

PORTALE: Well, the batteries -- the pingers have a two nautical mile range when they're actively pinging. As the battery starts to degrade, the frequency will actually get lower and lower and lower and the range will go down. The frequency goes lower because there's a ceramic ring in there that creates the acoustic sound. And as it has less and less power, it -- the output goes down. So you'll hear both of those items. And the range could go down until it's inaudible. You know, a mile or less than a half a mile.

PAUL: All right. Dukane director, Chris Portale. Chris, thank you so much for being with us.

PORTALE: No problem. Thank you.

PAUL: We appreciate it this morning. So Australia's prime minister, as you heard, we've been saying how he's really asserting his true confidence that this plane has been located because of these pings. But the Malaysian government, they are pretty hesitant.

(COMMERCIAL BREAK)

BLACKWELL: Welcome back. If the search for 370 is zeroing in on the right place, it's a challenge to say the least in that stretch of the Indian Ocean. And we want to give you some perspective about just how deep we're talking about here. At the very top of this animation, that is sea level. And when people go scuba diving for recreation, they go down about 130 feet. The Empire State Building, by comparison, is just over 1200 feet. And the bottom of the Grand Canyon, just over 5200 feet. The deepest diving sea mammal gets to more than 9800 feet. Now, even further down, the wreckage of the titanic was found at a depth of 12,500 feet. And the towed pinger locator that we've been talking about, which listens for signals from the black boxes, that's at about 10,000 feet below the surface. And the pings that have been picked up in the search for the plane are more than 13,000 feet below the surface. So although Australian officials are optimistic that they're now looking at the right place, there are challenges when we're talking about these kinds of depths. About three miles down, in darkness, with silt that can be incredibly thick. It's a difficult environment, to be sure. And it's been said, actually, that we know more about the surface of the Moon than the bottom of the ocean. Christi?

PAUL: So Victor, let's talk about this. As we hear conflicting points of view now on the search for Flight 370, Australia's prime minister confident that searchers have detected signals from the missing jet. Malaysia's transport minister, though, says, he is not so sure. Let's talk to Sumnima Udas. She's live in the Malaysian capital at Kuala Lumpur. Good morning, to you. Sumnima, I wanted to ask, what is prompting this hesitation from Malaysian authorities?

SUMNIMA UDAS, CNN CORRESPONDENT: Christi, the Malaysian authorities are hesitating because they say until they actually find the black box, they remain cautiously optimistic. Have a listen.

(BEGIN VIDEO CLIP)

HISHAMMUDDIN HUSSEIN, MALAYSIAN TRANSPORT MINISTER: Signals, they need to be verified. I totally agree with Angus Houston that any lead -- and this might be one of the more cautiously optimistic leads that we have because the signals are similar to a black box.

(END VIDEO CLIP)

UDAS: The acting transport minister going on to say all of this needs to be verified, and if, in fact, those signals are coming from the black box, then the new phase, the next phase of this search will begin. And that is actually the underwater search.

PAUL: You know, Sumnina, I think some of the things that people can't get out of their heads is what it has been like for these family members. What are they saying about this new information?

UDAS: Well, the family's reaction here has been overwhelmingly consistent and that is until they actually see the evidence for themselves, until they actually see the debris, they will not believe, they cannot believe that their loved ones are no longer alive. We've been talking to a family here, a father and mother who lost their only son. And the mother continues to call her son almost every day. She genuinely believes that he is still alive. We just got a message from a mother of the Iranian -- one of the Iranian passengers. And she says that she is still having sleepless nights. She still can't understand how that plane could have flown for so many hours and no one could have noticed. She says she hopes the Americans are still on top of this investigation because she's lost hope in the Malaysian authorities. And she says she's having a very difficult time believing that he is no longer alive until she actually sees the evidence.

PAUL: And who could blame them? I mean anybody who has kids or somebody they love and they don't have any evidence, of course that's where they're going to go with it. Thank you so much. Sumnima Udas, we appreciate it. Victor?

BLACKWELL: All right, Christi. Thanks. We've talked a lot about the search for those pings from the 370'sblack boxes. And to find them, we talked about the depth of the water, but the searchers have a lot more than deep water to deal with. Tom Foreman has more. Tom, good morning.

TOM FOREMAN, CNN CORRESPONDENT: Hi, Christi. Hi, Victor. We've been talking a lot about the devices that have been put into the water. They are to try to locate where these pings are coming from. The towed pinger locator, that's produced four solid hits so far. There have also been attempts to put in things like sonobuoys to listen - to see if they can pick up anything. But any listening device in the water here is going to face one real challenge out there at least. You've got to get around it somehow. And the challenge is what's called the sound fixing and ranging layer. This is about a half mile down. It's a naturally occurring phenomenon. And it's a layer where sound moves less quickly than it does in the ocean below or above it. A lot of different reasons. Salinity, water pressure, temperature. But the results are something really to contend with. If sound is coming up here and it hits this lair, because this is slower, it can essentially bend that sound and make it go at a very different angle than it was a moment ago. And then it may come out where you don't expect it at all. Also, in some cases, it may come up, hit the layer, and start ping-ponging between the top and the bottom of it. And by some theories, particularly with lower sounds, it may go many, many, many miles before it comes out. This may explain why a pinger that shouldn't be heard more than three miles away is being located in a range of some 17 miles. Because as it's coming up, it's possible that these anomalies, these strange things that happen to sound in deep water are affecting that signal. And they've got to overcome that and crush it down to the actual location before they go under water and start mapping very much. Victor, Christi?

BLACKWELL: Wow. It's a marine science lesson for all of us. Tom Foreman, thank you very much. And still to come, this is huge. And now, some big-name websites are coming in to fight this huge problem, rushing to patch a newly discovered security gap. We'll tell you if you're affected and how you can keep your information safe.

Also, we'll talk more about the technology being deployed. We're learning together here in this hunt for Flight 370.

(COMMERCIAL BREAK)

PAUL: Have a lot to talk about this morning, especially in terms of Malaysia Airlines Flight 370 and the search, but we do have other news going on.

BLACKWELL: Yes, we do have other news. And when you have other news, who do you talk to? This morning, we are calling him other news Nick. Nick Valencia is with us. Nick, good morning.

VALENCIA: Let's start in the Ukraine this morning, where gunmen stormed and took control of an administrative building in the eastern part of the country. Take a look at this video. Officials are headed to the scene. Meanwhile, NATO's chief is urging Moscow to pull back troops from the Ukrainian border. He released new satellite images showing the Russian military buildup. Moscow is calling the photographs outdated.

The court is in recess until Monday in the murder trial of Oscar Pistorius. The prosecutors accused the Olympic sprinter of changing his story. Pistorius testified he thought he heard an intruder before he fired several shots through a door fatally wounding his girlfriend. The prosecutor called that story "improbably". He said Pistorius intentionally shot Reeva Steenkamp after a heated argument.

The United States is following through on its word, refusing to issue a visa to this man, the man that Iran picked to be its new ambassador to the United Nations. U.S. officials say Hamid Aboutalebi has ties to the 1979 takeover of the American embassy in Tehran. Aboutalebi says he acted only as a translator and negotiator and denies his taking part in the initial occupation of the embassy.

The Duke and Duchess of Cambridge continue their three-week tour of New Zealand. Today William and Katherine visited the town of Cambridge, where they laid a wreath at a war memorial, honoring New Zealand's fallen soldiers. They also met with well-wishers during a short walk on the grounds.

Now, some big-name Web companies are racing to patch the Heartbleed bug. The security hole has allowed leaks from a safety feature that was supposed to keep your online communications private. Several sites including Yahoo! and Google already patched the bug. That means it's safe to change your password on those sites. CNN's Laurie Segall has more on how the bug works.

(BEGIN VIDEOTAPE)

LAURIE SEGALL, CNN CORRESPONDENT: Your bank account information, your emails, your passwords. Some of the most sensitive information you store on the Internet. You trust these companies to keep your data safe. But security researchers recently learned that information might not have been kept safe at all. A bug in the code that encrypts your personal information on websites may have been broken for two years, giving hackers lots of access to your personal data. The bug is called Heartbleed, and it affected 80 percent of Websites, including big ones you've heard of. OkCupid, Amazon, Yahoo!. So what are we talking about here? Think about when you go to a website that's https. Now, s means secure. This is how you know you are going to secure website. Well, here's the eye-opening thing about this hack. In the last couple of years that you've gone through these sites, with that "s" for secure, that doesn't necessarily mean your information has been safe. Heartbleed lets potential hackers utilize a tool that enables one computer to test if another computer is online. It's called the heartbeat check. With this hack, the heartbeat check could force a computer to diverge secret information, including the keys to the encryption code.

Once hackers have the keys to this, it's potentially game over. Your user names, passwords, all that sensitive data you thought was safe is essentially up for grabs. Sorry to say, it gets even worse: the Heartbleed bug leaves no traces, so you have no idea if or when you've been hacked. Now, of course, these sites are scrambling to get rid of the bug, but here's the thing: it might be days or even weeks before the entire Web has been fixed. So, what can you do about it? Well, right now you might actually have to sit tight. Because a lot of these websites are still trying to update their code and get rid of this bug. But once they have, you should definitely go in and change your passwords. And as always, be very cautious about the information you put out there.

(END VIDEOTAPE)

VALENCIA: Our thanks to CNN's Laurie Segall. Victor, Christi, right back to you.

BLACKWELL: All right, Nick Valencia, thank you very much.

So these sonobuoys. We are learning about them. They've been dropped from planes, they've been used in the - for this missing plane. What are sonobuoys?

PAUL: Yeah, you said it. We're learning here together. We're going to check it out in a moment.

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BLACKWELL: Time is of the essence in the search for these black boxes, and especially if they're relying upon on these pings from the locator beacons. Because the batteries powering the flight data recorders are likely soon to die, if they aren't dead already.

PAUL: Right. A tow pinger locator and sonobuoys dropped from an airplane are being used in the hunt for this. But CNN's Chad Myers is going to help us here. Take a look at how these things work. Chad?

CHAD MYERS, CNN CORRESPONDENT: Christi, Victor, in the big picture, this is pretty low tech. Technology used years ago, tens of years ago to listen for submarines because we didn't have the technology that we do now to listen for submarines. You throw this thing out the back of an airplane, let it splash down. It's about the size of the big roll of wrapping paper that you use for Christmas. You know, not the small ones, but the big fat ones that you get a lot of paper on. So, it falls into the water. And it's connected to the surface by a wire, 1,000-foot wire. It's connected to the float that's on top that eventually pops open when it hits the water. And then it sends the signal back up to the airplane. So very low tech. All it's doing is listening. It's not pinging. It's not making any noise. It's not looking for the bottom. It's just sitting there as a microphone, waiting to hear, hopefully, here are the pings from the pinger. Now, this thing can listen for whales, they can listen for volcanos, they can listen for anything. It's just literally a microphone. That's all it is - it's a microphone sitting there at the bottom of the ocean. And then it will take that sound and send it back up to the airplane, the radio signals either VHF or UHF, get back up to the airplane and it says, wait, we hear something. We hear pinging from that one buoy. They're not just going to send out one. They're going to send out many in a pattern, see which one can pick up the signal the strongest, that way we know which sonobuoys is the closest.

Christi, Victor.

BLACKWELL: All right. Chad Myers, thank you, Chad.

PAUL: We are just edging toward the 7:00 hour officially on a Saturday morning. You don't even have to get out of bed. It's Saturday. Enjoy it. I'm Christi Paul.

BLACKWELL: At least not for a few hours. I'm Victor Blackwell. This is "NEW DAY" Saturday. And there's a lot going on this morning. A huge standoff in Nevada. A long-time rancher and the government are fighting over federal land. And this is becoming violent now.

PAUL: Also, the big announcement that Colbert is going to be taking over after Letterman retires. That's the buzz in the entertainment world today. We're going to take you live to the Ed Sullivan Theater.

BLACKWELL: We're going to start with the latest on the search for Flight 370.